Since the beginning of the global financial crisis of 2008, credit rating agencies (CRAs) have become a major topic of political discussion. Yet even before the crisis began, the need for the regulation of these companies was debated in both the US and the EU - with varying policy outcomes. This paper examines why the United States introduced regulatory measures for CRAs in 2006 while such an intervention in the rating business was rejected by the European Union at the time. The author argues that the different policy outcomes can be explained by so-called domestic sources. In other words, the strategies derived from the preferences of US domestic economic actors and regulators differed greatly from those in the EU. Moreover, the author shows that regulatory agencies played a decisive role in legislative processes on both sides of the Atlantic.